1. Field of the Invention
The present invention relates to a card device for high-speed wireless data communication.
2. Description of the Related Art
Wireless data communications signify that a person in movement connects a mobile communication terminal, such as a portable computer or personal digital assistant (PDA), to a cellular phone and transmits and receives various data wirelessly.
In order to overcome the inconvenience of separate connection to a cellular phone, card devices for wireless data communication containing mobile communication modems have been developed.
FIG. 2 is a block diagram schematically showing a mobile communication modem, for example, a MSM 5500 mobile communication modem manufactured by Qualcom™ Inc. (referred to hereinafter as an “MSM modem”) which is embodied in a wireless data communication card device.
As shown in FIG. 2, the MSM modem includes a CDMA (Code Division Multiple Access) processor 31, a universal processor 32, a USB (Universal Serial Bus) interface 33, a UART (Universal Asynchronous Receiver/Transmitter) serial bus interface 34, and a universal interface bus 35.
The card device equipped with the MSM modem is mounted to a mobile communication terminal, such as a portable computer or PDA, to conduct wireless data communication via the USB interface 33 and UART serial bus interface 34.
A MSM modem including a high-speed CDMA processor with a maximum data rate of 2.45 Mbps satisfies the date rate of a USB interface, but the modem has a difficulty in connecting with a PCMCIA (Personal Computer Memory Card International Association) interface and limits the date rate of a UART serial bus interface. For this reason, such an MSM modem including the high-speed CDMA processor cannot be contained and used in a card device for wireless data communication.